Deut. 19-21 [The Message]

God gave the Hebrews ways to clear their conscience if they had sinned. A clear conscience is important for the believer. In fact, it is one of our goals in the Christian life.

Now the end (goal) of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned: [1 Tim. 1:5]

When we take communion, it is a time to examine ourselves and be cleansed. It increases the power of our prayer.